Data Structures and Algorithms (DSA)

New Post: How should a new node with the same value be inserted?

antonyd — Mon, 26 Nov 2012 00:55:41 GMT

Say a tree has an existing node with value 1. If another node of same value is to be added , which side should it go?

Your document states to go RIGHT : " where the left subtree of x contains nodes with values < x and the right subtree contains nodes whose values are >= x ."

Whereas an article from Stanford states to go LEFT : "all elements in its left subtree are less-or-equal to the node (<=), and all the elements in its right subtree are greater than the node (>)."

Provided code sample ignores duplicates. I am not sure which side to take?

New Post: Why does ICommonBinaryTreeNode have a TNode generic parameter?

antonyd — Sun, 25 Nov 2012 18:15:36 GMT

Also, CommonBinaryTree<TNode,TValue> restricts the use of TNode to a ICommonBinaryTreeNode, i.e the node should ONLY have LEFT and RIGHT children. This also means that I cannot implement any generic node say TOP,BOTTOM and hence I am still wondering the rationale behind TNode in ICommonBinaryTreeNode<TNode,TValue>. Hope I am making some sense , please correct my understanding.

New Post: Why does ICommonBinaryTreeNode have a TNode generic parameter?

antonyd — Sun, 25 Nov 2012 17:12:42 GMT

A relatively easier implementation of this interface could be

public interface ICommonBinaryTreeNode<T>
    {
        ICommonBinaryTreeNode<T> Left { get; set; }

        ICommonBinaryTreeNode<T> Right { get; set; }

        TValue Value { get; set; }
    }

But, I understand the intention of the authors that the Left & Right children could a node of any other type. Can you cite an tree example that could take advantage of the generic parameter <Tnode> ?

New Post: Error loading Dsa.test.csproj project in monodevelop.

antonyd — Sun, 25 Nov 2012 00:14:26 GMT

If you are trying to see the code using monodevelop, then you could most likely run into an error when loading Dsa.test.csproj. This is because of a projectguid reference to mstest (though all projects are Nunit based). To overcome this problem , remove this line from Dsa.Test.csproj

<ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4....

Just thought someone might benefit

Source code checked in, #96133

Project Collection Service Accounts — Mon, 01 Oct 2012 21:40:31 GMT

Upgrade: New Version of LabDefaultTemplate.xaml. To upgrade your build definitions, please visit the following link: http://go.microsoft.com/fwlink/?LinkId=254563

Source code checked in, #96132

Project Collection Service Accounts — Mon, 01 Oct 2012 21:33:03 GMT

Checked in by server upgrade

New Post: Boundary conditions

justINcoder — Thu, 21 Oct 2010 15:06:12 GMT

Hi moderators

I was going through your code project. I started with Algorithms/Numbers.cs. Some of the boundary cases have not been checked. Please go through the list and consider applying them.

I am enlisting a few here. More to come.

1. Fibonacci, GCD, Tobinary, ToOctal methods have to check for integer overflow if given the max value of integer.

2. ToBinary, ToOctal methods need to check what will happen if the number is zero (0).

Thanks

Created Issue: Remove method of Heap throws IndexOutOfRangeException [11793]

sthumma — Fri, 20 Aug 2010 04:14:44 GMT

public void RemoveThrowsIndexOutOfRangeException4001281575269()
{
Heap<int> heap;
bool b;
heap = new Heap<int>();
b = heap.Remove(0);
}

Created Issue: AddBefore of DoublyLinkedList throws NullReferenceException [11792]

sthumma — Fri, 20 Aug 2010 04:13:44 GMT

public void AddBeforeThrowsNullReferenceException6181281577058()
{
DoublyLinkedList<int> doublyLinkedList;
doublyLinkedList = new DoublyLinkedList<int>();
doublyLinkedList.AddLast(0);
DoublyLinkedListNode<int> s0 = new DoublyLinkedListNode<int>(0);
s0.Next = (DoublyLinkedListNode<int>)null;
s0.Previous = (DoublyLinkedListNode<int>)null;
doublyLinkedList.AddBefore(s0, 0);
}

Created Issue: AddAfter of DoublyLinkedList throws NullReferenceException [11791]

sthumma — Fri, 20 Aug 2010 04:12:30 GMT

public void AddAfter101281577093()
{
DoublyLinkedList<int> doublyLinkedList;
doublyLinkedList = new DoublyLinkedList<int>();
doublyLinkedList.AddLast(0);
DoublyLinkedListNode<int> s0 = new DoublyLinkedListNode<int>(0);
s0.Next = (DoublyLinkedListNode<int>)null;
s0.Previous = (DoublyLinkedListNode<int>)null;
doublyLinkedList.AddAfter(s0, 0);
Assert.IsNotNull((object)doublyLinkedList);
Assert.IsNotNull(doublyLinkedList.Head);
Assert.AreEqual<int>(0, doublyLinkedList.Head.Value);
Assert.IsNotNull(doublyLinkedList.Head.Next);
Assert.AreEqual<int>(0, doublyLinkedList.Head.Next.Value);
Assert.IsNull(doublyLinkedList.Head.Next.Next);
Assert.IsNotNull(doublyLinkedList.Head.Next.Previous);
Assert.IsTrue(object.ReferenceEquals
(doublyLinkedList.Head.Next.Previous, doublyLinkedList.Head));
Assert.IsNull(doublyLinkedList.Head.Previous);
Assert.IsNotNull(doublyLinkedList.Tail);
Assert.IsTrue
(object.ReferenceEquals(doublyLinkedList.Tail, doublyLinkedList.Head.Next));
Assert.AreEqual<bool>
(false, ((CollectionBase<int>)doublyLinkedList).IsSynchronized);
Assert.AreEqual<int>(2, ((CollectionBase<int>)doublyLinkedList).Count);
}

Created Issue: CopyTo of BinarySearchTree throws ArgumentException [11790]

sthumma — Fri, 20 Aug 2010 04:10:13 GMT

public void CopyToThrowsArgumentException3051281576371()
{
BinarySearchTree<int> binarySearchTree;
binarySearchTree = new BinarySearchTree<int>();
binarySearchTree.Add(0);
int[] ints = new int[0];
binarySearchTree.CopyTo(ints);
}

Created Issue: NullReferenceExceptions in BinarySearchTree [11789]

sthumma — Fri, 20 Aug 2010 04:05:12 GMT

Following test cases throw NullReferenceExceptions BinarySearchTree.

1.

public void RemoveThrowsNullReferenceException4301281576193()
{
BinarySearchTree<int> binarySearchTree;
bool b;
binarySearchTree = new BinarySearchTree<int>();
binarySearchTree.Add(134217985);
binarySearchTree.Add(0);
b = binarySearchTree.Remove(134217985);
}

2.

public void RemoveThrowsNullReferenceException541281576193()
{
BinarySearchTree<int> binarySearchTree;
bool b;
binarySearchTree = new BinarySearchTree<int>();
binarySearchTree.Add(-2109603803);
binarySearchTree.Add(16);
binarySearchTree.Remove(0);
b = binarySearchTree.Remove(-2109603803);
}

3.

public void RemoveThrowsNullReferenceException8101281576193()
{
BinarySearchTree<int> binarySearchTree;
bool b;
binarySearchTree = new BinarySearchTree<int>();
binarySearchTree.Add(0);
binarySearchTree.Add(0);
binarySearchTree.Add(0);
b = binarySearchTree.Remove(0);
}

Created Issue: FormatException thrown by public methods in Algorithms namespace [11788]

sthumma — Fri, 20 Aug 2010 04:01:21 GMT

1.
public void ToBinaryThrowsFormatException1771281578009() {
int i;
i = Numbers.ToBinary(0);
}

2.

public void ToOctalThrowsFormatException1771281578040() {
int i;
i = Numbers.ToOctal(0);
}

Created Issue: IndexOutOfRangeException thrown by public methods in Algorithms namespace [11787]

sthumma — Fri, 20 Aug 2010 04:00:04 GMT

Following test cases throw IndexOutOfRangeException.

1.

public void RadixSortThrowsIndexOutOfRangeException4131281576033() {
IList<string> iList;
string[] ss = new string[2];
ss[0] = "\0";
ss[1] = "\u00ff";
Sorting.RadixSort((IList<string>)ss, 1);
}

2.
public void AnyThrowsIndexOutOfRangeException3591281576865() {
Strings.Any("\t\t", "\t\t");
}

3.

public void IsPalindromeThrowsIndexOutOfRangeException4721281576877() {
bool b;
b = Strings.IsPalindrome("++");
}

4.

public void ReverseWordsThrowsIndexOutOfRangeException881281576919() {
string s;
s = Strings.ReverseWords("\t\t");
}

5.
public void WordCountThrowsIndexOutOfRangeException6361281576940() {
int i;
i = Strings.WordCount("");
}

6.

public void MedianLeftThrowsArgumentOutOfRangeException4241281575753()
{
IList<int> iList;
int[] ints = new int[0];
iList = Sorting.MedianLeft<T>((IList<int>)ints);
}

Created Issue: Overflow exceptions thrown in many classes from Algorithms namespace [11786]

sthumma — Fri, 20 Aug 2010 03:49:12 GMT

Invoking public methods in Numbers class throws overflow exceptions due to not handling of specific scenarios as follows:

1. Number.Fibonacci(int.MaxValue)
2. Numbers.GreatestCommonDenominator(-1, int.MinValue)

Source code checked in, #63489

_TFSSERVICE — Tue, 27 Jul 2010 20:28:19 GMT

Checked in by server upgrade

Created Issue: Return value not as expected. SinglyLinkedList class, Remove method [8858]

mrmarri — Sun, 27 Sep 2009 19:29:45 GMT

When the SinglyLinkedList<string> contains {“”,null} and item to remove is “\0”, Remove method returns true, when the expected return value is false.

Created Issue: Return value not as expected. Heap class, Remove method [8857]

mrmarri — Sun, 27 Sep 2009 19:27:51 GMT

When the heap size < 4 and contains no item of value 0, the Remove method still returns true, when the expected return value is false
[Test]
public void testMethod()
{
Heap<int> actual = new Heap<int> {1,2,3};
actual.Remove(0);
}

Comment: The problem is due to the default assignment of array of size 4 in the constructor

Created Issue: IndexOutOfRangeException: Heap class, Remove method [8856]

mrmarri — Sun, 27 Sep 2009 19:25:35 GMT

When the heap contains no elements and item to remove is 0, the Remove() method throws IndexOutOfRangeException
[Test]
public void testMethod()
{
BinarySearchTree<int> bst = new BinarySearchTree<int>{};
bst.Remove(0);
}

Created Issue: NullReferenceException: BinarySearchTree class, Remove method [8855]

mrmarri — Sun, 27 Sep 2009 19:22:49 GMT

When the root == elementToRemove && tree's count > 1, then Remove method throws a NullReferenceException

[Test]
public void testMethod()
{
BinarySearchTree<int> bst = new BinarySearchTree<int>{0,0};
bst.Remove(0);
}